This application is based upon and claims priority of Korean Patent Application No. 98-24554, filed Jun. 27, 1998, in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an optical disk recording/reproducing apparatus and a method thereof, and, more particularly, the present invention relates to an apparatus for and method of recording/reproducing audio and video data on a re-recordable optical disk in real time.
2. Description of the Related Art
A typical digital video disk (DVD) read only memory (ROM) video player reproduces audio and video data using a disk. FIG. 1 is a diagram of a conventional DVD-ROM video format. As shown in FIG. 1, the conventional DVD-ROM video format is comprised of a program chain (PGC) including programs, cells for logically dealing with data, and video objects (VOBS) in which audio and video data are recorded.
If a movie has been recorded into first and second volumes, the entire movie is represented by a PGC, and each of the first and second volumes can be represented by programs. Furthermore, each of the programs can be divided into several smaller units (i.e., cells) in consideration of a random access, and data included in each cell exists in a partial area of the VOBS.
A manufacturer of a disk in the DVD-ROM video format produces original audio and video data items in the form of PGCs, including the programs and the cells, and provides the result to users.
As shown in FIG. 1, program chain information (PGCI) is the connection information of several programs, and VOBS is a video object (VOB) collection in which actually-compressed audio and video data items have been recorded. One or more programs exist in one PGCI, and one program is comprised of a collection of one or more cell units. Each cell is a type of recording/reproducing unit, and audio and video data exit in the VOBS. The PGCI includes only program information, such as the position of audio and video data or the recording/reproducing time existing in the VOBS. The VOB in the VOBS is subdivided into video object units (VOBU) which are used as random access units of a disk recording/reproducing apparatus. In general, the VOBU consists of motion picture experts group (MPEG) video data and audio data multiplexed in units of a sector.
The relationship between the title and the PGC in a conventional DVD-ROM video disk will now be described. For example, a title can correspond to an entire movie, and is the largest unit of a data structure from a user""s standpoint. When manufacturing the DVD-ROM video disk with such a title, a data structure is formed wherein one title may comprise one PGC, as shown in FIG. 2A, or one title may comprise several PGCs as shown in FIG. 2B, according to the manufacturer""s intention. When the title comprising several PGCs, as shown in FIG. 2B, is reproduced in sequence, PGC#1 and PGC#2 are reproduced, then one of PGC#3, PGC#4, and PGC#5 is selected and reproduced, and finally PGC#6 is reproduced. The contents of PGC#3, PGC#4, and PGC#5 may be different. Alternatively, PGC#3, PGC#4 and PGC#5 may have different editions of the same content.
From a user""s standpoint, the title has such a large concept that it can be divided into several chapters or parts of title (PTT) to allow a scene to rapidly jump to the next scene. In the case of a music compact disk (CD), an entire album recorded in the CD corresponds to one title, and each of the songs corresponds to a chapter or PTT. The programs and cells are reproduction and recording units determined by a user according to the properties of data. In the PGC corresponding to a title concept, the PTT is divided by the content of data and logically provided to the user.
The PTT also has its own information in the form of a PTT search pointer table among areas of information on the title. FIG. 3 illustrates a conventional PTT search pointer table. As shown in FIG. 3, the conventional PTT search pointer table is comprised of a PTT search pointer table information area, and PTT search pointers existing in a title. In FIG. 3, the PTT search pointer table information area includes information on the number of PTT search pointers. Each of the PTT search pointers indicates a point in time when a PTT starts, and, as shown in FIG. 4, is comprised of a program chain number (PGCN) and a program number (PGN). The PGCN represents the number of a program chain (PGC) to which the PTT pertains, and the PGN represents the number of a program in the PGC. A large amount of PTT information is moved from a current position, where PTT information is being reproduced, to the next PTT, and then is reproduced, when a user has received the next PTT command via an external input device.
In the DVD-ROM video format, the programs making up a PGC, as shown in FIG. 1, are consistent with the content actually recorded on a disk. That is, an area in a specific range includes programs through a special manufacturing process on the basis of the contents recorded on the disk, and a specific program can be defined to be selected from the several programs and used as PTT. Further, the program units are divided in accordance with the contents of recorded data, so that the PTT information can use the program units. However, in an apparatus for recording/reproducing audio and video data in real time, units such as programs, cells, etc., cannot be produced in accordance with the contents of data recorded on a disk, unless special information on the contents of the recorded data is provided in real time. Therefore, if the PTT is produced according to the prior art, the PTT information is meaningless to users.
It is an object of the present invention to solve the above-noted problems of the prior art and to provide an optical disk recording and reproducing method of recording and reproducing part of title (PTT) information depending on real-time recorded data contents on a rewritable optical disk.
It is another object of the present invention to provide an optical disk recording and reproducing apparatus for recording and reproducing part of title (PTT) information depending on real-time recorded data contents on a rewritable optical disk.
It is still another object of the present invention to provide an optical disk recording medium by which a user can randomly access part of title (PTT) information within specific units, such as cells or programs, for reproduction and recording on a rewritable optical disk.
Objects and advantages of the present invention are achieved with an optical disk recording method of recording audio and video data on a rewritable disk in real time, comprising the steps of: recording the audio and video data in a specific area on the disk; forming a cell with a part of the recorded audio and video data; forming a program with the cell; forming a part of title (PTT) with a specific portion of the recorded audio and video data; and recording information on the formed cell, program, and PTT on the disk.
The step of forming a cell may comprise forming a plurality of cells and the step of forming a program comprises forming a program with the plurality of cells.
The step of forming the cell may comprise forming the cell based on a recording start and a recording end command from a user.
The step of forming the program may comprise forming the program based on the recorded information on the cell.
The step of forming the PTT may comprise forming the PTT at a regular reproducing time interval with reference to a time for reproducing the cells.
The disk recording method may further comprise the step of randomly accessing the PTT within a specific unit of a data structure for reproduction or recording. The specific unit of the data structure for reproduction or recording may be the cell. The specific unit of the data structure for reproduction or recording may be the program.
Objects and advantages of the present invention are achieved in accordance with embodiments of the present invention with an optical disk reproducing method of reproducing previous and next units of a specific unit on a rewritable disk in real time, the method comprising the steps of: reading and decoding a video object unit (VOBU) including a specific unit for reproducing, prior to reading and decoding other units, in response to input of a key for reproducing the previous and next units of the specific unit; and displaying decoding data on a screen in response to the decoding data arriving at the specific position for reproducing in the specific unit during decoding.
Objects and advantages of the present invention are achieved in accordance with embodiments of the present invention with an optical recording/reproducing apparatus for recording and reproducing audio and video data on a rewritable disk, comprising: a key input unit to input commands for reproducing previous and next data of a specific unit; and a controller to control recording of information on the disk about a cell including part of the audio and video data, a program including the cell, and a part of title (PTT) including a specific portion of the audio and video data, reading and decoding a video object unit (VOBU) including the specific unit for reproducing prior to recording and decoding other units, and displaying of the decoding data on a screen when the decoding data arrives at the specific position for reproducing in the specific unit during decoding.
Objects and advantages of the present invention are achieved in accordance with embodiments of the present invention with a disk recording medium to access recorded data at predetermined intervals, comprising: a cell including part of predetermined data, the cell being set as reproduction and recording units; and information representing a position from a start of the cell to a specific position.
The disk recording medium may further comprise a plurality of cells including part of predetermined data, the plurality of cells being set as reproduction and recording units, wherein the information represents a position from a start of the respective cells to the specific position.
The reproduction and recording units may be randomly accessible. Further, the position from the start of the respective cells to a specific position is defined as a reproduction time.
Objects and advantages of the present invention are achieved in accordance with embodiments of the present invention with an optical disk recording/reproducing apparatus for recording and reproducing audio and video data on a rewritable disk, comprising a key input unit to receive a command key for recording a part of title (PTT) at a specific position during recording of audio and video data; and a controller to control storage of PTT information representing a specific position being reproduced at a point in time when the command key is input from the key input unit, and to control recording of reproduction-completed PTT information on the disk.
The information representing the specific position being reproduced may include information on a predetermined unit used during reproduction at the specific position, and offset position information within the predetermined unit.
The offset position information may be a reproduction time from a start of the predetermined unit to the specific position.
Objects and advantages of the present invention are achieved in accordance with embodiments of the present invention with an optical disk reproducing method of reproducing a previous and a next unit of a specific unit on a rewritable disk in real time, the method comprising reading and decoding a video object unit (VOBU) including a specific unit for reproducing, prior to reading and decoding other units, in response to input of a key for reproducing the previous and next units of the specific unit; and displaying decoding data on a screen in response to the decoding data arriving at a specific position for reproducing the specific unit during the decoding.
Objects and advantages of the present invention are achieved in accordance with embodiments of the present invention with an optical disk recording/reproducing method of recording and reproducing audio and video data on a rewritable disk, the method comprising setting a specific position while recorded audio and video data is reproduced; storing information on the specific position in a separate area; and and recording the information on the specific position on the rewritable disk.
The information on the specific position may include information on a predetermined unit used during reproduction at the specific position, and information on an offset position within the predetermined unit.
The information on the offset position may be a reproduction time from a start of the predetermined unit to the specific position.